Mammals Living Year-Round in Antarctica: Only Seals

No land mammals live year-round in Antarctica. The only native, year-round resident mammals are seals (Pinnipedia) — all marine, hauling out on ice/land.

Antarctic Seal Species (Year-Round)

1. Weddell Seal (Leptonychotes weddellii) — most southerly mammal; dives 600m, 80 min; maintains breathing holes in fast ice
2. Crabeater Seal (Lobodon carcinophaga) — most abundant seal (~15M); specialized krill-filtering teeth; pack ice
3. Leopard Seal (Hydrurga leptonyx) — apex predator; eats penguins, seals, krill; solitary; dives 1,500m
4. Ross Seal (Ommatophoca rossi) — rarest; Ross Sea; big eyes, trilling calls; squid/fish
5. Antarctic Fur Seal (Arctocephalus gazella) — sub-Antarctic islands, Peninsula; dense fur; 95% on South Georgia
6. Southern Elephant Seal (Mirounga leonina) — largest seal (♂ 4,000 kg); Peninsula, sub-Antarctic; deep diver

Seasonal Visitors

• Whales (summer): Humpback, Minke, Orca, Blue, Fin — feed on krill
• Humans (research stations): 1,000–5,000 seasonally

Why No Land Mammals?

• Extreme cold (-60°C winter), darkness, no vegetation, isolation (30M years)
• Antarctic Treaty prohibits non-native species introduction

Seals are the true Antarctic citizens—evolutionary marvels of cold adaptation.